E46 Xi Forum The E46 XI was produced from 01-05 in sedan and touring body styles. Powered by either a 2.5L inline 6 in the 325xi or a 3.0L inline 6 330xi. Discuss all thing about BMW AWD E46 'Xi' here.

Now that Iíve fixed my coolant issues, it seems another issue has arrived to replace it..

The other day I noticed a bit of vibration coming from the rear of the car. I didnít look into it much and kept driving.
I drove it to work again today and the vibration is getting worse. Itís coming from the rear of the car, I canít pinpoint if itís one side or the other, or the center. It vibrates enough to reach my front mirrors. It starts around 20 mph and seems to be loudest around 20-50. Iíve noticed when I accelerate the noise quiets down for the most part. To note though, if I put the car in neutral and rev it while the noise is occurring, it doesnít change. Only when it is in gear.

I am going to rule out wheel bearings and tires as these have already been replaced not long ago. Upon research and my own intuition I am leaning toward a rear axle issue or somthing with the driveline/guibo. I looked briefly under the car and didnít see any torn axle boots or fluid so I am a bit puzzled. Could it be the rear dif? I havenít gotten to changing the fluid on that yet.

Does anyone else have any ideas, or has anyone experienced this? It started randomly after I drove home one night. Was idling in a parking lot for about 15 minutes then drove home and noticed it.

Have you checked your center drive shaft? Check out the condition of the guibo(flex disc) and center support bearing. Both are common maintenance items. Definitely service both diffs if you get the chance, cheap insurance.
Regards

Have you checked your center drive shaft? Check out the condition of the guibo(flex disc) and center support bearing. Both are common maintenance items. Definitely service both diffs if you get the chance, cheap insurance.
Regards

Any tips on diagnosing if the guibo and bearing are bad visually? I took a look at them and they appear old and worn but so does a lot of the stuff beneath the car, haha. donít really know how to tell if itís bad persay

The factory likes to look at deflection rates(IE lock up drive line to measure the wear/flex, etc..). Having said that, I find guibo will get hard and it will slam into gear, per say. The flex disc will have cracks. I like to replace them between 60-80k, along with center support bearings. With the center support bearing, it's usually the rubber portion that is wiped out before the bearing. You'll find the center support portion will have loads of movement which it should not. If you can, check out the condition of the motor and transfer case mount.
Regards

The factory likes to look at deflection rates(IE lock up drive line to measure the wear/flex, etc..). Having said that, I find guibo will get hard and it will slam into gear, per say. The flex disc will have cracks. I like to replace them between 60-80k, along with center support bearings. With the center support bearing, it's usually the rubber portion that is wiped out before the bearing. You'll find the center support portion will have loads of movement which it should not. If you can, check out the condition of the motor and transfer case mount.
Regards

Do you know if the guibo and center support bearing are universal parts for the E46?
I have a 330xi and most sites list fitments only for 325i 330i etc not xi
I did find it for more expensive on a couple other sites, but these sites listed fitment of the xi in addition to the regular RWD cars. So Iím wondering if they are even different? Iíd rather not pay extra for the same part on a different site as long as it fits.

So the guibo and center support bearing, do you think that will take care of it? It definitely appears they are the culprits just wondering if anything else should be replaced while Iím in there.
Thanks

Hop on over to realoem.com and put the last 7 digits of your VIN in. Then you can navigate over to the driveshaft page and check the part numbers. When you click on a part it will show you what other cars share the part.

Do you know if the guibo and center support bearing are universal parts for the E46?
I have a 330xi and most sites list fitments only for 325i 330i etc not xi
I did find it for more expensive on a couple other sites, but these sites listed fitment of the xi in addition to the regular RWD cars. So Iím wondering if they are even different? Iíd rather not pay extra for the same part on a different site as long as it fits.

So the guibo and center support bearing, do you think that will take care of it? It definitely appears they are the culprits just wondering if anything else should be replaced while Iím in there.
Thanks

My car is RWD and not AWD like yours, but I've been living with a slight vibration issue on my car for a while now and I've traced it back to play in the rear driveshaft U-joint closest to the differential.

If you're going through the trouble of removing the exhaust and pulling the shaft out to replace the center suppt bearing and guibo it's worth checking to make sure the U-joints are good first before pressing on a new CSB and reassembling everything. Used rear driveshafts can be had for around 50-100 bucks at the salvage yard vs 1000 for a new/refurbished one.

Symptoms of warn driveshaft U-joints are a notchy feeling as you move the joint by hand and you may also notice some play if you twist the U-joint is if it were rotating under load.

The U-joint should also not be too tight either and should move freely in all directions. Typically what happens when the joint fails is that first the bearing seals will fail allowing the grease to sling out (which may be noticeable on the underside of the car near the joint) and then the bearings will get stiff from lack of lubrication and corrosion. After that if the bearings don't completely lock up they tend to wear themselves sloppy over time.

Unfortunately BMW went with a press in type needle bearing caps so they are not easily serviceable like other joints that hold the caps in with snap rings. There are no grease zerks either so it's not like you can just add more grease.

In the middle of replacing the CSb and guibo. Noticed they donít look all that bad now that I have a clear view of them. Iím still going to replace them as I already have the parts- and fingers crossed that it fixes it. But Iím starting to get nervous that the problem will remain since they donít appear that bad. I included a photo of the rear u joint which looks rusted, but I donít notice any damage to it or any of the driveshaft components really. What do you guys think? Would you expect more damage to these parts if they are causing such significant vibration? There are no visible cracks in the guibo or damage to the bearing.

Update- installed guibo and CSB. Vibration has lessened but is sadly still there. It feels how the car felt a few weeks ago when the vibration first started. Iím assuming there is vibration elsewhere that caused the guibo and csb to wear out as well and get even worse. So I fixed that but the root cause still seems to exist. Any thoughts? Vibration pretty much completely goes away under acceleration. Itís not tires or suspension related as far as I can tell. Very small chance of axle or dif issue but I didnít see any issues after inspecting. The rear u joint on the driveshaft didnít feel bad either. Really lost on where to go from here.

You may also want to check and make sure rear transmission mount hardware is tight. I'm talking about nuts at the small rubber isolators that mount to the trans to the aluminum cast crossmember. I've had those nuts loosen up in the past even though I thought they were torqued properly. I believe those are single use distorted thread locking nuts that you should replace every time.

EDIT:
Not sure, but the transmission mounting setup may be different if you have auto transmission, I was referring to manual transmission.

You may also want to check and make sure rear transmission mount hardware is tight. I'm talking about nuts at the small rubber isolators that mount to the trans to the aluminum cast crossmember. I've had those nuts loosen up in the past even though I thought they were torqued properly. I believe those are single use distorted thread locking nuts that you should replace every time.

EDIT:
Not sure, but the transmission mounting setup may be different if you have auto transmission, I was referring to manual transmission.